Judging from their history and the leaders they brought for (e.g. Saladin or Karim Khan-e Zend), I don't think that's an overestimation. Especially considering them leading the fight against ISIS and other Islamist groups. They have even gone as far as battling ISIS outside of Kurdish regions. Bin Laden was caught thanks to Kurdish intelligence services. I could go on with giving examples, but no other majority muslim nation in the Middle-East has done anything close to that.

Are other muslims fighting ISIS? Definitely. But they aren't fighting ISIS for the right reasons, but for other sectarian or religious reasons (e.g. Shia vs Sunni bullshit. This doesn't exist among Kurds, even though both sects are largely presented among Kurds).

My sentence is not to say "bad Kurdish muslims" don't exist; they do. But, generally speaking, Kurds are one of the few nations who haven't done anything that has affected Islam's image negatively; the Kurdish forces are, in fact, the only truly secular forces in the region, one even going as far as accepting LGTB members in its political party (HDP).

If it weren't for Kurds, Islam wouldn't even have had Saladin. And I don't think I am overestimating things when stating that Saladin is, without a doubt, one of the major figures who managed to establish a good image of Islam in Europe for centuries. Hell, he's even listed in purgatory in Dante's "Inferno", and not in hell like more prominent Islamic figures (e.g. Mohammed), and this is from a Medieval European work, by a person living in the country of the Pope; and it was Saladin's victory in Jerusalem that lead to the death of a Pope.